Re: [tarantool-patches] [PATCH 1/3] netbox: allow to create a netbox connection from existing socket

["v.shpilevoy@tarantool.org" <v.shpilevoy@tarantool.org>]

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> 22 марта 2018 г., в 22:33, Konstantin Osipov <kostja@tarantool.org> написал(а):
> 
> * Vladislav Shpilevoy <v.shpilevoy@tarantool.org <mailto:v.shpilevoy@tarantool.org>> [18/03/22 22:18]:
> 
> The patch generally looks good to me, I can only nitpick on new
> things. 
> 
> How about renaming do_connect to connect_impl and wrap_connect to
> wrap_socket or simply wrap, or maybe bless or imbue?

Ok.

> 
>> +        if existing_connection then
>> +            connection = existing_connection
>> +            existing_connection = nil
> 
> Why is it necessary to set it to nil?

On reconnect it will call protocol_sm again, and it must no get old existing_connection again.

> 
>> +            assert(greeting)
>> +            assert(greeting.protocol ~= 'Lua console')
> 
> Please keep in mind that in Lua there are no asserts - it's a
> runtime check.

Ok.

>> +
>> +local function wrap_socket(connection, greeting, url, opts)
>> +    if connection == nil or type(greeting) ~= 'table' then
>> +        error('Usage: netbox.wrap_socket(socket, greeting, [opts])')
>> +    end
>> +    if greeting.protocol == 'Lua console' then
>> +        error('Can not wrap console socket')
>> +    end
>> +    opts = opts or {}
>> +    if not opts.user and not opts.password then
>> +        opts.user, opts.password = url.login, url.password
>> +    end
>> +    return do_connect(url.host, url.service, opts, connection, greeting)
>> +end
> 
> Looks like you should make the next step, i.e. take the piece of
> do_connect which establishes a connection and move it to
> connect(), and then you can the remains of do_connect into wrap()
> and call wrap() connect().
> 
> Did you try to do it? Had any trouble?

Connection establishment must be in connect inside create_transport, because even if an existing socket was wrapped, it still can have opts.reconnect_after option and the following scenario:
socket = ...
con = netbox.wrap_socket(socket, ..., {reconnect_after = ...})
--
-- use connection ...
--

Suppose it is broken due to error. Then netbox will try to establish a new connection after 'reconnect_after' seconds.
> 
> -- 
> Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
> http://tarantool.org <http://tarantool.org/> - www.twitter.com/kostja_osipov <http://www.twitter.com/kostja_osipov>

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